Nabb, Indiana Weather Forecast Discussion

964
FXUS63 KLMK 121937
AFDLMK
Area Forecast Discussion
National Weather Service Louisville KY
337 PM EDT Fri Sep 12 2025
.KEY MESSAGES...
*  Unseasonably warm temperatures are expected over the next week,
   with highs in the upper 80s and lower 90s each day.
*  There is a slight chance of rain showers across southern IN and
   northern KY Saturday night into Sunday morning; otherwise, dry
   weather is expected over the next week.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 337 PM EDT Fri Sep 12 2025
This afternoon, the region sits on the edge of sfc high pressure
centered over the northeast US. Divergent flow out of the high has
resulted in light NE winds and has brought lower dewpoints into the
area, with most obs in the 50s. Temperatures as of 19Z are generally
in the mid 80s, with a few upper 80s across southern KY and
southwest IN. While a few cumulus clouds have developed along and
west of I-65, coverage is less than in previous days, and no rain is
expected over the next 24 hours.
Tonight, light winds around sunset should go calm in most locations
overnight, with little more than scattered high clouds passing
during what should be another mostly clear night. Radiational
cooling should again be fairly efficient, allowing temperatures to
fall into the mid-to-upper 50s in rural areas and the low 60s in the
urban heat islands. Wouldn`t be surprised if locations in deeper
valleys again fall into the low 50s Saturday morning.
On Saturday, an upper-level trough is expected to descend across
southeast Canada and the northeast US, with the Ohio Valley being on
the southwestern fringe of this feature. At the same time, upper
ridging will spread from the Ozarks into the mid-Mississippi Valley,
setting up northerly mid- and upper-level flow. An area of higher
PWATs (1.5-1.6") is expected to be drawn from the Mississippi Valley
toward the Ohio Valley as the upper trough swings by Saturday
afternoon and evening. Initially, this should just lead to
increasing high clouds with drier air remaining near the surface.
Temperatures tomorrow should be 1-2 degrees above persistence as
light low-level SW flow and subtle height increases are expected
ahead of the trough passage. Highs should be in the upper 80s and
lower 90s across most of the area, though afternoon dewpoint
temperatures in the 50s should keep heat indices suppressed.
Saturday night into Sunday morning, a weak west-southwesterly LLJ
should increase moisture in the previously dry sfc-700 mb layer,
mainly along and north of the Ohio River. As a mid-level vort lobe
swings through in association with the edge of the trough, modest
forcing combined with increasing moisture should support the
development of scattered showers and a few storms across central
Indiana. While the environment will be less supportive for
precipitation across southern IN and central KY, hi-res and medium-
range guidance suggests that at least isolated to scattered showers
could survive into southern IN and northern KY. As a result, PoPs
are increasing Saturday night into Sunday morning. However, we`re
only expecting 20-30% coverage at this time, and precipitation
amounts are expected to be light (generally 0.10" or less).
Temperatures will be milder given increasing clouds and moisture,
with more areas remaining in the 60s.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 337 PM EDT Fri Sep 12 2025
The long term forecast continues to remain warm and dry. The ridge
axis will move over the region on Sunday, which will bring slightly
increased heights and slightly warmer temperatures. Broad surface
and low level high pressure/heights will lead to very weak winds at
the surface, despite the forecasted dry air mix down in the
afternoons. In the afternoons we will see high temperatures in the
upper 80s and low 90s each day this week. Dew points will be in the
upper 50s most times, but dry air mix down may bring some areas into
the low 50s. Therefore, although it will be warm, lower humidity
will help to keep more comfortable conditions.
Towards the end of next week, the GFS brings a trough through the
northern Ohio Valley and the Euro brings troughing over the
northeastern CONUS. The position of this troughing will determine if
we remain dry later next week. Will continue to monitor these trends
over the coming days.
Given our current long term forecast, there is no mention of
precipitation. Therefore, drought conditions and elevated fire
weather conditions are expected to worsen.
&&
.AVIATION /18Z TAFS THROUGH 00Z SUNDAY/...
Issued at 155 PM EDT Fri Sep 12 2025
VFR flight categories are expected this afternoon and evening as
light east-northeast winds (4-8 kts) continue. Overnight, winds will
be either calm or light and variable with mostly clear skies
expected. Dewpoint temperatures should fall enough this afternoon
that early morning fog should be limited Saturday morning, although
HNB and BWG could still see occasional MVFR vsbys between 08-13Z.
Tomorrow, winds will remain light with mainly scattered cirrus
expected during the day.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.
&&
$$
SHORT TERM...CSG
LONG TERM...SRW
AVIATION...CSG

NWS LMK Office Area Forecast Discussion